Bow saw



@ctZZ, 1935. BURKHARDT 2,018,437

BOW SAW V Filed May 31, 1954 Patented Oct. 22, 1935 UNITED STATES PATENTOFFICE BOW SAW Hermann Burkhardt, Weiningen, Switzerland Application May31, 1934, Serial No. 728,391 In Switzerland June 10, 1933 1 Claim.

which can be handled easier in places difiicult of access and whicheasily can be taken apart and put together. To attain these objects thenew saw consists of two straight wooden uprights of the same shape, ametal bow with ends bent down at an angle loosely abutting against andengaging into recesses of the uprights in the manner of knuckle-joints,tension-rods actuated by wingscrews attached at one end to the angularpoints of the metal bow by means of articulated joints and lying at theother end in the prolongation of the mean part of the bow in s1its ofthe uprights open on top, a blade carried parallel to the mean part ofthe bow, said bow, tension rods and blade forming the only transversalparts between the uprights.

The accompanying drawing exemplifies an adaption of the invention andshows:

Fig. 1a lateral view of the saw, partly in section;

Fig. 2the detached bow;

Fig. 3-the blade with the uprights in another position; and

Fig. 4-a section along line I-I of Fig. 2.

Blade l at its ends is provided with adjusting pins 2 connected by meansof articulated joints, said pins passing through bores of the uprights3, the latter consisting of straight wooden pieces and the bladepossessing handles 4 bearing on the uprights. 5 is a metal bow, havingin the design shown an intermediate straight part 6 with ends I bentdown at a sharp angle. Ends 8 of said ends 1 rest loosely, with someplay, in recesses 9 of the uprights 3. Tension-rods I l, carryingwing-screws [3, pass through slits 12 open on top, of uprights 3, saidtension-rods acting on straight part 6 ofbow 5 5 by means of forks l9jointed loosely to said how. When tightening or slackening the blade, byturning the wing-screws i3, ends 8 form fulcrums for the uprights 3 onbow 5.

My saw has the following advantages: there 10 are but two horizontaltransverse parts, that is blade I and the mean part of bow 5 parallel toit, so that between the two there is provided much room to work in;since the ends of bow 5 are bent down at an angle, wing-screws II are 15aligned with the mean part of bow 5 (see Fig. 1) giving rise tofavorable tensile stresses; since ends 8 rest loosely in uprights 3, andthe wingscrews II sit in s1its i2 open on top, the saw can easily betaken apart and put together. The 20 straight wooden pieces of theuprights 3 can easily and cheaply be made.

I claim:

A buck hand saw having two straight wooden uprights of the same shape, ametal bow with 25 ends bent down at an angle loosely engaging inrecesses of said uprights, tension-rods with wingscrews at one endattached to the angle-points of the bow by means of a joint and at theother end lying in alignment with the mean part of the bow in s1its ofthe uprights open on top, a blade parallel to the mean part of the bow,said blade, bow and rods forming the only transversal parts between theuprights.

HERMANN BURKHARDT.

